Ryanair boss Michael O'Leary has threatened to sue the European Commission for damages amid claims its official travel agency discriminates against low-cost carriers.

The complaint comes after the businessman was told at the end of last year that the commission's travel agency could not book him on to a Ryanair flight to speak at a conference on innovation in Brussels and was instead offered a ticket on rival Aer Lingus.

Mr O'Leary has made an official complaint to the watchdog that oversees the EC's spending.

Ryanair's lawyers have asked the European Court of Auditors, to look at the "legality, regularity and financial soundness" of the policy. The airline boss told The Daily Telegraph: "The point we'll be making is here you have a bloated commission wasting money hand over fist while it's preaching the value of austerity to the Irish."

An EC spokeswoman said it didn't have a "policy" against booking with low-cost carriers.

She insisted that the EC's agency, American Express Business Travel, is unable to make reservations with low cost carriers because it does not subscribe to the bookings system used.